This post contains Dr. Fox’s post and an excerpt from Dr. Helman’s post, both of which are are excellent brief summaries about Kawasaki Disease. And the post contains links to more important references in Additional Resources below.
But References (1), (2), and (4) are articles that should reviewed by every pediatrician.
Vigilance can be the most difficult part of our job [that is, caring for pediatric patients]. After being inundated with kids who have all started back to school and swapped their various viruses with one another and now have new fevers (after having just got rid of their previous virus), it is easy to become complacent. So sometimes it is best to have some preset “alarms” that go off when certain criteria are met. For instance, set an alarm that gets your attention anytime someone presents with “Fever for 5 days.”
While “Fever for 5 days” may be due to numerous conditions and should make you ponder infectious as well as oncologic processes, the one that needs specific consideration is Kawasaki Disease. We have discussed Kawasaki Disease in the past (see Morsel), but this time let us focus on the aspects that may lead to a Delayed Diagnosis of Kawasaki Disease.
Kawasaki Disease (KD) Basics
- KD is an acute febrile vasculitis that occurs in children.
- It is the LEADING CAUSE OF ACQUIRED HEART DISEASE among children in North America and Japan.
- The cause is currently unknown.
- 85% of cases occur in children < 5 years of age (which means there are cases in older children).
- Recurrence rate is low (~4%).
It’s a Clinical Diagnosis
- The diagnosis of KD is considered confirmed by the presence of Fever for 5 or more daysand4 of the 5 following criteria, provided that the illness cannot be explained by other known disease (see Morsel for common mimics).
- Bilateral Conjunctival Injection
- Mucous Membrane Changes of the Upper Respiratory Tract: injected pharynx, fissured lips, strawberry tongue.
- Changes of the Peripheral Extermities: peripheral edema, peripheral erythema, periungual desquamation.
- Polymorphous Rash: it really can be almost any type of rash.
- Cervical Adenopathy
Incomplete Kawasaki Disease
- The child has prolonged fever, but only 2 or 3 of the characteristic features (so not a complete complement of criteria).
- While the child has an incomplete set of criteria, he/she has as the same risk for developing coronary artery aneurysms.
- When you are entertaining this possibility, lab values (ESR/CRP) can be helpful in risk stratify the patient.
- It may also be a case when you actually need an ECHO done in the ED to help determine the child’s management (See Newburger article for evaluation algorithm [I have placed a link to the article in Additional Resources, Reference (1)]
Timing is Everything
- 20% – 25% will go on to develop coronary artery aneurysms if untreated.
- Intravenous Immunoglobin (IVIG) in addition to Aspirin lower the rate of developing coronary artery aneurysms to 3% – 5%.
- The benefit of IVIG and Aspirin is seen if it is administered within the first 10 days of illness!
- When therapy is initiated after Day 10, the incidence of coronary artery aneurysms increases ~3 times (so 9%-15%).
- Vascular injury is evident as easly as 1 week after onset of fever.
- Ideally, treatment should be started on or before Day 7 of illness.
Potential Causes of Delayed Diagnosis of Kawasaki Disease
- The diagnostic characteristics are not specific and overlap with other entities.
- The diagnostic characteristics may be transient and do not have to be all present concurrently!
- Incomplete Kawasaki Disease – come on this isn’t even fair!
- Lack of vigilance!! We need to keep it on the DDx list!
Who is at greatest risk for having Delayed Diagnosis of Kawasaki Disease?
- Children < 6 months of age
- Children who present with < 4 criteria (Incomplete KD)
- Those who lived a greater distance from the clinical center – that makes sense. May have poorer access to care.
- Specific clinical centers also had higher rates of delayed diagnosis – perhaps pointing towards physicians not considering the Dx as much as other centers.
Moral of the Story:
Stay vigilant. When someone presents with a report of prolonged fever, reconsider Kawasaki Disease and be especially keen to revisit the potential of KD in those who are < 6 months and in those who Incomplete KD may be the diagnosis
The following is an excerpt from Reference (3) in Resources from Dr. Helman:
The painless red eye
- Acute systemic vasculitis of mucosal vessels of unknown etiology in children mnemonic Warm C‐R‐E‐A‐M
- Warm ‐ Fever >39°C for 5 days, PLUS 4 of the 5 following signs (or less in ‘atypical’ form of the disease):
- C ‐ Conjunctivitis, bilateral non‐exudative
- R ‐ Rash, polymorphic (e.g. urticarial, maculopapular) and on the body (not vesicular nor bullous)
- E – Edema or erythema of the hands, eventually leading to desquamation
- A ‐ Adenopathy with at least one anterior cervical lymph node >1.5cm (not generalized over the whole body)
- M – Mucosal involvement: fissured red lips, strawberry tongue
- Incomplete Kawasaki: American Guidelines ‐ “If the typical clinical findings of Kawasaki disease are present in a child with fever for less than five days, or if three classic features plus coronoary artery findings on echocardiography are found, the diagnosis still can be made and treatment initiated”
- Features that go against the diagnosis of Kawasaki: exudative conjunctivitis or pharyngitis, discrete intra‐oral lesions, bullous or vesicular rash and generalized lymphadenopathy
- Pearls: almost always look unwell/very irritable, fever is minimally responsive to anitpyretics, often have peri‐anal erythema, and there is often a sharp demarcation at the wrist and ankles from the redness in the extremities
- Abnormal tests – High platelets, WBC, ESR and CRP, LFTs (especially AST/ALT), sterile pyuria in urine (WBC present but no bacteria), as well as normochromic, normocytic anemia and hyponatremia
- Treatment – High dose ASA and IVIG, best if treat within 10d of onset of symptoms (lower complication rate)
(1) Diagnosis, treatment, and long-term management of Kawasaki disease: a statement for health professionals from the Committee on Rheumatic Fever, Endocarditis and Kawasaki Disease, Council on Cardiovascular Disease in the Young, American Heart Association. [PubMed Abstract] [Full Text HTML] [Download Full Text PDF from HTML link]. Circulation. 2004 Oct 26;110(17):2747-71.
(3) Episode 9: Nontraumatic Eye Emergencies from Dr. Anton Helman’s outstanding podcast series Emergency Medicine Cases. This podcast is over two hours long and it is worth every minute! The discussion of Kawasaki disease is well summarized in the notes above but is worth listening to also from 59:00 to 75:00 approximately.
(4) Echocardiography in Kawasaki Disease [Full Text PDF]. Jan 18, 2012